Method of producing a detergent impregnated cleaning device



Nov. 26, 1963 A. POLITZER ETAL 3,112,219

METHOD OF PRODUCING A DETERGENT IMPREGNATED CLEANING DEVICE Filed Dec. 11. 1961 INVENTORS ALFRED POLITZER, JAMES TENG,

WILLIAM L. KENDALL, PAO'CHI WANG ATTORNEY United States Patent C) 3 112 219 METHOD or rno nume A DETERGENT IMPREGNATED CLEANING DEVICE Alfred Politzer, James Teng, William L. Kendall, and

Pao-Chi Wang, Cleveland, Ohio, assignors to Nylonge Corporation, Cleveland, (lhio, a corporation of Ohio Filed Dec. 11, 1961, Ser. No. 153,466 4 Claims. (Cl. 117-98) The present invention relates generally to improvements in cleaning devices and it relates particularly to an improved detergent impregnated sponge and to a method of producing the same.

Scouring pads formed of steel wool and impregnated with soap are common and have been widely employed. However, they possess the numerous drawbacks accompanying the use of steel wool scouring pads for among other reasons that they rapidly rust and deteriorate, producing unsightly discolorations, and possess the hazard of easily pricking the skin of the user and frequently causing festering. It has been proposed to impregnate a sponge with a soap or synthetic detergent but these have not proven commercially successful. Where soap or a solid detergent is employed as an impregnant the resulting product is rigid and hence highly unsatisfactory. Furthermore, the sponge impregnated with the solid detergent is greatly deformed and of unattractive appearance. On the other hand where a sponge is impregnated with a fluid detergent, the sponge possesses a slimy unpleasant feeling and the detergent is rapidly dissipated.

t is thus a principal object of the present invention to provide an improved method of producing improved cleaning devices.

Another object of the present invention is to provide an improved method for producing a detergent impregnated cleaning device.

Still another object of the present invention is to provide an improved method for producing soap impregnated sponge.

A further object of the present invention is to provide an improved method for producing a detergent impregnated cleaning device in which the detergent is efficiently employed and dispensed at a highly suitable rate.

Still a further object of the present invention is to provide an improved method of the above nature, winch method is simple, economical and efiioient, and requires a minimum of equipment.

The above and other objects of the present invention will become apparent from a reading of the following description taken in conjunction with the accompanying drawing wherein:

FIGURE 1 is a front perspective view of a cleaning device embodying the present invention; and

FIGURE 2 is a longitudinal sectional view of an apparatus with which the present process may be practiced.

It has been discovered that a sponge impregnated with a solid gel containing a detergent as a dispersant medium possesses many advantages over the detergent impregnated cleaning devices heretofore available. It possesses a pleasant dry or slightly moist feel, it is soft, flexible and compressible, and is of attractive appearance and of excellent dimensional stability in that there is very little difference in size and shape between the normally moist sponge and the detergent gel impregnated sponge. Furthermore, the detergent is dispensed at a highly suitable rate when in use and is not dissipated when not in use. The detergent gel is advantageously a reversible gel and is applied in accordance with the method of the present invention by immersing the wet sponge in the molten gel and compressing and releasing the sponge while so immersed. The sponge releases water to the melt and absorbs the melt which completely impregnates the sponge,

A the amount of melt remaining therein being then adjusted by squeezing the sponge outside the melt a predetermined amount. Upon removal of the sponge and the cooling thereof the gel solidifies and the impregnated sponge possesses the above characteristics.

It has been found that a reversible gel formed of water and a polyhydric alcohol as a dispersing medium, and a water soluble soap as a dispersant medium may be employed to great advantage. The polyhydric alcohol is preferably a glycol, such as propylene glycol, ethylene glycol, diethylene glycol, triethylene and higher polyethylene glycols. It has been found advantageous to include in the gel an emulsifying agent which will disperse calcium and magnesium soaps and thus prevent them from destroying household detergent foams. An emulsifying agent which is advantageously employed is the reaction product of a fatty acid and diethanol amine for example, Monamide, a lauric aoid-diethanolamine condensate although other fatty acids may be employed such as capric, cyristic and others. The reversible gel should preferably have a melting point between about 40 C. and C. What is meant by a soap is a salt of a fatty acid, such as the sodium salts of the tallow or vegetable fatty acids.

The composition of the gel impregnating the sponge advantageously comprises 5% to 60% water, 15% to 40% polyhydric alcohol, preferably propylene glycol or ethylene, diethylene, triethylene or higher polyethylene glycols or mixtures thereof, and between 20% and 55% of a water soluble soap. In addition, the gel may include between 5% and 30%, based on the total weight of the above ingredients, of an emulsifying agent such as Monamide.

In impregnating a sponge, for example a regenerated cellulose sponge with the soap containing gel, a gel melt is formed, by heating the soap, water, polyhydric alcohol and emulsifying agent in the above proportions the melt being a homogeneous solution of a relatively low viscosity. The sponge, containing water between 2.5 and 3 times the bone dry weight of the sponge, is immersed in the gel melt and compressed to between 15% and 25% of its normal volume from 4 to 12 times so as to release water into the gel melt and absorb the gel melt. It should be noted that the composition of the gel remaining in the sponge after impregnation is approximately that of the gel melt which generally reaches an equilibrium composition depending upon the temperature thereof and other production parameters. Thus, the percentage of water may be controlled by varying the temperature of the melt, the higher the temperature, the greater the water evaporation rate and the lower the water concentration.

Among the important advantages achieved with the present cleaning device and method, particularly when applied to artificial sponges such as regenerated cellulose sponges, is that the gel impregnated sponge is substantially equal in shape and dimensions to the original moist sponge and is of closely controlled attractive appearance. The impregnated sponge possesses a pleasant feel and is soft, flexible and compressible. Moreover, the soap may be dispensed at a suitable rate and is not dissipated when the device is not in use. Where the emulsifying agent is employed, no scum formation or breaking of the foam is evident even in the presence of other detergents or in hard water.

Another important advantage of the present procedure is the obviation of the necessity of any drying step in the production of regenerated cellulose sponge and the elimination of the need for additional plasticizing agents and possibly fungicide. Both the drying of the sponge and the use of plasticizing agents are expensive and their elimination appreciably reduces the cost of the end product.

In FIGURE 1 of the drawing, there is illustrated a preferred embodiment of the present invention which is designated by the reference numeral and includes a soap gel impregnated sponge body member 11 of rectangular prismatic configuration and a non-woven fibrous mat 12 adherent to a face thereof. The mat 12 is advantageously a low density three dimensional non-woven, random distributed fibrous Web formed of synthetic organic fibers which are adhesively bonded at their points of intersection by resin globules which carry a finely divided abrasive material. The sponge body member 11 is formed of regenerated cellulose and the mat 12 is attached thereto by embedment therein of the fibers at the interface of the sponge and mat. A method of producing the composite mat 11 and sponge 12 is described in the copending patent appliaction of Alfred Politzer et al., Serial No. 87,398, filed February 6, 1961. The regenerated cellulose body member 11 is impregnated with a solid gel of the composition earlier set forth containing 5% to 60%, water for example 45%; to 40% propylene glycol, for example and to soap, for example 35%; and 5% to 30% Monamide based on the total weight of all other ingredients, for example 20% of the combined weight of Water, glycol and soap. The total weight of the impregnant is between 3.5 and 4 times the bone dry weight of the sponge, for example, 3.7 times.

Referring now to FIGURE 2 of the drawing, the reference numeral 13 generally designates an apparatus with which the present process may be practiced and which includes a longitudinally extending vat 14 carrying a molten, fluid, soap containing gel or melt G. The gel G is maintained at a predetermined temperature by heating elements 16 in heattransfer relation with the gel G and controlled in any well known manner to regulate the liquid gel or melt temperature. Immersed in the liquid gel G are a plurality of longitudinally spaced transversely extending squeeze rolls 17 positively driven at the peripheral speed of the web W being treated, the spacing between the rolls 17 of each pair being adjustable in any suitable manner. Disposed at the discharge end of the tank 14 above the level of the gel melt G is another pair of adjustable, squeeze rolls 18. A plurality of transverse rods 19 are provided to guide the web W along its path through the tank 14. Trailing the feed end of the tanks 14 are another pair of positively driven adjustable squeeze rolls 20 which are employed to control the moisture content of the web W prior to impregnation with the melt G.

The web W is of the structure of the composite as sembly of sponge 11 and mat 12 and may be continuously produced in the manner described in the previously identified patent application of Politzer et al. A continuous web of mat 12 and a layer of viscose sponge forming material are brought into superposition with the mat being partially embedded in the viscose sponge forming mass layer and the viscose is then coagulated and the cellulose regenerated. The composite web is then washed and bleached and squeezed so that the sponge body has a water content of between 2.5 and 3 times the sponge bone dry weight, for example, 2.7 times.

The tank 14 contains the molten gel G of the composition specifically set forth above and is maintained at a temperature between 70 C. and 105 C., for example 90 C., at which temperatures the melt is of low viscosity, and the melt G is at its specific equilibrium composition at the aforesaid temperature of 90 C. As the Web W traverses the path between successive squeeze rolls it releases the water contained therein and is impregnated with the melt G. After it leaves the melt G the web W passes between the squeeze rolls 18 where excess melt is expressed therefrom to bring the gel carried by the sponge part of the web W .to between 3.5 and 4.5 times the sponge bone dry weight for example 3.7 times. The amount of gel carried by the mat 12 is only a few per cent by reason of the low absorption, thereof. The web W is then cut to the desired size and shape and packaged.

If the sponge, impregnated in accordance with the above example is packaged immediately after impregnation it will be damp to the touch but not sticky. On the other hand, if the impregnated sponge is allowed to cool to room temperature it will loose some water, about 5% to 10% and feel somewhat dryer to the touch. If the sponge is oven dried at C. for 24 hours it will become dry and brittle with a water content below the required minimum but upon exposure to normal room humidity for more than a half hour it will regain sufiicient water to acquire its desirable physical properties.

The sponge produced in accordance with the above example possesses excellent physical appearance, good color, pleasant odor, and no foamy residue or encrustations on the surfaces thereof. The sponge has a pleasant feel, being dry, soft, somewhat flexible and springy with no evidence of stickiness no matter how the sponge is pinched or squeezed. The sponge will retain its soft, flexible, nontacky, non-sticky characteristics within a very wide range of humidity and temperature conditions and requires no additional plasticizer or special packaging conditions. The presence of the fatty acid-diethanolamine condensate permits the cleaning device to be used in conjunction with low to high concentrations of synthetic detergents with no loss of foam due to the formation of hard water soap scums. A further consequence of the preesnce of the fatty acid-diethanolamine condensate is the immediate effectiveness of the soap in water by reason of the inhibition of the formation of hard water soap scums which results in the prompt production of foam with the first trace of soap added to the water.

While there have been described and illustrated preferred embodiments of the present invention, it is apparent that numerous alterations, omissions and additions may be made Without departing from the spirit thereof. For example, the impregnation of the sponge may be effected in other manners than that described such as by employing an intermittently operated press instead of the successive squeeze rolls.

What is claimed is:

l. A method of producing a cleaning device comprising impregnating a wet sponge with a molten composition normally solid at room temperature and containing a polyhydric alcohol and a water soluble soap and cooling said impregnated sponge to form a solid gel therein having, as a dispersing medium, water and said polyhydric alcohol and, as a dispersant medium, said water soluble soap.

2. The method of claim 1 wherein said molten composition contains Water.

3. The method of claim 1 wherein said impregnation is effected by compressing and expanding said sponge in the presence of said molten composition whereby to substantially displace the water in said sponge with said molten composition.

4. The method of claim 1 wherein said sponge prior to impregnation contains between 2.5 and 3 times the bone dry weight thereof of water.

References Cited in the file of this patent UNITED STATES PATENTS 1,619,105 Eggan Mar. 1, 1927 1,819,435 Moses Aug. 18, 1931 1,868,862 Washburn July 26, 1932 1,969,900 Pickett Aug. 14, 1934 2,226,075 Rowe Dec. 24, 1940 2,403,821 Morgan et a1 July 9, 1946 2,495,066 Jones Jan. 17, 1950 2,583,183 Marvin et al Jan. 22, 1952 2,591,481 Webster Apr. 1, 1952 2,807,584 Rushton Sept. 24, 1957 3,080,688 Politzer Mar. 12, 1963 FOREIGN PATENTS 759,136 Great Britain Oct. 17, 1956 

1. A METHOD OF PRODUCING A CLEANING DEVICE COMPRISING IMPREGNATING A WET SPONGE WITH A MOLTEN COMPOSITION NORMALLY SOLID AT ROOM TEMPERATURE AND CONTAINING A POLYHYDRIC ALCOHOL AND A WATER SOLUBLE SOAP AND COOLING SAID IMPREGNATED SPONGE TO FORM A SOLID GEL THEREIN HAVING, AS A DISPERSING MEDIUM, WATER AND SAID POLYHYDRIC ALCOHOL AND, AS A DISPERSANT MEDIUM, SAID WATER SOLUBLE SOAP. 